com.aspc.DBObj

Class Path

java.lang.Object

com.aspc.DBObj.Path

Direct Known Subclasses:

LookupPath

public class Path
extends java.lang.Object

Path allows us to reference one object from another. The syntax allows for
a record set or a particular row of an inward link. Outward links are simpler as
one field can only be linked to one object. Paths may be chained together to reference
nearly any object from any other object within the database.

The path syntax is used in many places like database formulas and from within excel functions.

Person id name mother father

Invoice id price client

Job id inv qty price prod

Prod code cost name

Payment id amount inv

1) Invoice price ( inward)
[job:inv#*].price

2) Job Price ( outward)

qty * prod.cost

3) Mother's name (outward)

mother.name

4) children name ( inward)
[mother].name

5) Invoice's product name ( in & out)
[job:Inv#*].prod.name

6) person's name
name

7) Invoice's second job qty
[job:inv#1].qty

8) grand children
[mother#*].[mother#*].name

9) Grandmother's name
mother.mother.name

Type	Syntax
outbound to object	class:link link class:link.key_field
put to a field	class:link.field link.field
simple field	field
inward link	[class:link#*] [class:link] [link]
chained	[class:link#*].link.field

THREAD MODE: MULTI-THREADED shared

Since:

March 22, 2001, 1:39 PM

Author:

Nigel Leck

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	DISPLAY_CLASS_NAME Display type Class Name
static java.lang.String	DISPLAY_GLOBAL_KEY Display type Global Key
static java.lang.String	DISPLAY_ROW_UID Display type Row UID
static java.lang.String	PARAM_DISPLAY The PARAMETER DISPLAY
static java.lang.String	PARAMS_OPTION_ENCODE encode
static java.lang.String	PARAMS_OPTION_HIDE hide
static int	RESULTS_ALL all results
static int	RESULTS_MEMORY_ONLY Only in memory results

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Path(DataSource ds) Creates a new Path without an actual supplied path.
	Path(DataSource ds, java.lang.String thePath) Creates a new Path.
	Path(DataSource ds, java.lang.String thePath, DBClassConcrete baseClass) Creates a new Path.

Method Summary

Modifier and Type	Method and Description
DBObject	createInwardTarget(DBObject base) Short hand method to create a inward linked object if missing.
protected Link	createLink(java.lang.String thePath, VirtualDB layer, DBClassConcrete baseClass) LookUpPath add behaviour
DBField	findTargetField() The field that this path points to.
java.lang.String	getAsciiDescription() The ASCII description of this path.
java.lang.String	getAsciiDescription(boolean longFormat) The ASCII description of this path.
java.lang.String	getAsciiDescription(boolean longFormat, DBObject base) The ASCII description of this path.
java.lang.String	getAsciiDescription(boolean longFormat, DBObject base, java.lang.String paramProcOption) The ASCII description of this path.
DBClassConcrete	getBaseClassConcrete() The DBClass that is the base of this path.
java.lang.String	getBinaryDescription() A "binary" version of the path.
java.lang.String	getBinaryDescription(boolean longFormat) A "binary" version of the path.
java.lang.String	getBinaryDescription(boolean longFormat, DBObject base)
DBResult	getResult(DBObject base, HintField hint) Returns a record set for all inward linked records.
DBResult	getResult(DBObject base, HintField hint, int type) Returns a record set for all inward linked records.
Link[]	getSteps() Returns a list of links that make up this path.
DBObject	getTarget(DBObject base) Returns the object that this path points to, start for the base object.
DBObject	getTarget(DBObject base, boolean createMissingObjects) Walks to the last object.
DBClassConcrete	getTargetClassConcrete() The DBClass that this path points to.
DBField	getTargetField() The field that this path points to.
FldParams	getTargetParams()
GlobalKey	getTargetRow() A short hand method to returns the RowId of the target object.
java.lang.Object	getValue(DBObject base) Returns the value for the target field from the target object and also is language aware
boolean	hasInwardLink() does this path have an inward link ?
boolean	isRuntimeEval() Is this path runtime evaluated.
boolean	isSimpleField() Does this path just point to a field within this class.
protected void	parse(java.lang.String thePath, DBClassConcrete baseClass)
java.lang.String	toString() Return the ascii version of the path.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

RESULTS_MEMORY_ONLY

public static final int RESULTS_MEMORY_ONLY

Only in memory results

See Also:

Constant Field Values

RESULTS_ALL

public static final int RESULTS_ALL

all results

See Also:

Constant Field Values

PARAMS_OPTION_HIDE

public static final java.lang.String PARAMS_OPTION_HIDE

hide

See Also:

Constant Field Values

PARAMS_OPTION_ENCODE

public static final java.lang.String PARAMS_OPTION_ENCODE

encode

See Also:

Constant Field Values

PARAM_DISPLAY

public static final java.lang.String PARAM_DISPLAY

The PARAMETER DISPLAY

See Also:

Constant Field Values

DISPLAY_ROW_UID

public static final java.lang.String DISPLAY_ROW_UID

Display type Row UID

See Also:

Constant Field Values

DISPLAY_GLOBAL_KEY

public static final java.lang.String DISPLAY_GLOBAL_KEY

Display type Global Key

See Also:

Constant Field Values

DISPLAY_CLASS_NAME

public static final java.lang.String DISPLAY_CLASS_NAME

Display type Class Name

See Also:

Constant Field Values

Constructor Detail

Path

public Path(@Nonnull
            DataSource ds,
            @Nonnull
            java.lang.String thePath)
     throws InvalidPathException

Creates a new Path.

Parameters:

ds - The data source for this path.

thePath - The actual path

Throws:

InvalidPathException - The syntax for the path is wrong or contains missing classes or fields.

Path

public Path(@Nonnull
            DataSource ds,
            @Nonnull
            java.lang.String thePath,
            @Nullable
            DBClassConcrete baseClass)
     throws InvalidPathException

Creates a new Path. Because a base class is passed a shorter version of the path syntax can be used.

Parameters:

ds - The data source for this path.

thePath - The actual path

baseClass - The base class to be used for this path.

Throws:

InvalidPathException - The syntax for the path is wrong or contains missing classes or fields.

Path

protected Path(@Nonnull
               DataSource ds)

Creates a new Path without an actual supplied path. Used by subclasses who want to parse the path later.

Parameters:

ds - The data source for this path.

Method Detail

getAsciiDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getAsciiDescription()

The ASCII description of this path. Uses class and field names. Defaults to the short version of the path.

Returns:

The text version of this path

getAsciiDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getAsciiDescription(boolean longFormat)

The ASCII description of this path. Uses class and field names. Defaults to the short version of the path.

Parameters:

longFormat -

Returns:

The text version of this path

getAsciiDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getAsciiDescription(boolean longFormat,
                                                                        @Nullable
                                                                        DBObject base)

The ASCII description of this path. Uses class and field names. The long format will always contain the base class. Passing a base object means that row offsets in inwards links can be converted to globalkeys

Parameters:

base - the base object

longFormat - A flag to get the format

Returns:

The text version of this path

getAsciiDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getAsciiDescription(boolean longFormat,
                                                                        @Nullable
                                                                        DBObject base,
                                                                        @Nullable
                                                                        java.lang.String paramProcOption)

The ASCII description of this path. Uses class and field names. The long format will always contain the base class. Passing a base object means that row offsets in inwards links can be converted to globalkeys Hide params will stop params contains within the link being added to the description

Parameters:

base - the base object

paramProcOption -

longFormat - A flag to get the format

Returns:

The text version of this path

hasInwardLink

@CheckReturnValue
public boolean hasInwardLink()

does this path have an inward link ?

Returns:

true if we have an inward link.

isSimpleField

@CheckReturnValue
public boolean isSimpleField()

Does this path just point to a field within this class. This is used within the DBQuery to determine if the path can be used within a select.

Returns:

true if this is just a field.

isRuntimeEval

@CheckReturnValue
public boolean isRuntimeEval()

Is this path runtime evaluated.

Returns:

the value

toString

@CheckReturnValue
 @Nonnull
public java.lang.String toString()

Return the ascii version of the path.

Overrides:

toString in class java.lang.Object

Returns:

The text version of a path

getBinaryDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getBinaryDescription()

A "binary" version of the path. It uses the id's of the classes and fields.

Returns:

The "binary" version

getBinaryDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getBinaryDescription(boolean longFormat)

A "binary" version of the path. It uses the id's of the classes and fields. The long format will always contain the base class.

Parameters:

longFormat -

Returns:

The "binary" version

getBinaryDescription

@CheckReturnValue
 @Nonnull
public java.lang.String getBinaryDescription(boolean longFormat,
                                                                         @Nullable
                                                                         DBObject base)

Parameters:

longFormat -

base - the base object

Returns:

the value

getTargetField

@Nullable
 @CheckReturnValue
public DBField getTargetField()

The field that this path points to.

Returns:

The target field

findTargetField

@Nonnull
 @CheckReturnValue
public DBField findTargetField()
                                                    throws java.lang.NoSuchFieldException

The field that this path points to.

Returns:

The target field

Throws:

java.lang.NoSuchFieldException - no target field for path

getTargetClassConcrete

@CheckReturnValue
 @Nullable
public DBClassConcrete getTargetClassConcrete()

The DBClass that this path points to.

Returns:

The target DBClass

getValue

@CheckReturnValue
 @Nullable
public java.lang.Object getValue(@Nullable
                                                              DBObject base)
                                                       throws java.lang.Exception

Returns the value for the target field from the target object and also is language aware

Parameters:

base - the base object

Returns:

the value

Throws:

java.lang.Exception - a serious problem

getTarget

@CheckReturnValue
 @Nullable
public DBObject getTarget(@Nullable
                                                       DBObject base)
                                                throws java.lang.Exception

Returns the object that this path points to, start for the base object.

Parameters:

base - The object to start our journey

Returns:

the target object.

Throws:

java.lang.Exception - a serious problem.

getTarget

@CheckReturnValue
 @Nullable
public DBObject getTarget(@Nullable
                                                       DBObject base,
                                                       boolean createMissingObjects)
                                                throws java.lang.Exception

Walks to the last object.

DBFile:folderId means the DBFile not the folder that it points to.

Parameters:

base - The object to start our journey

createMissingObjects - Is the target object doesn't exist should we create it.

Returns:

The target object

Throws:

java.lang.Exception - A serious problem occurred.

getTargetParams

@CheckReturnValue
 @Nullable
public FldParams getTargetParams()

Returns:

the value

getTargetRow

@CheckReturnValue
 @Nullable
public GlobalKey getTargetRow()
                                                    throws java.lang.Exception

A short hand method to returns the RowId of the target object.

Returns:

The row Id

Throws:

java.lang.Exception - A serious problem occurred

createInwardTarget

@Nullable
public DBObject createInwardTarget(@Nullable
                                             DBObject base)
                                      throws java.lang.Exception

Short hand method to create a inward linked object if missing.

Parameters:

base - The base object to start our journey.

Returns:

The created object

Throws:

java.lang.Exception - A serious problem occurred.

getResult

@CheckReturnValue
 @Nonnull
public final DBResult getResult(@Nullable
                                                            DBObject base,
                                                            @Nullable
                                                            HintField hint)
                                                     throws java.lang.Exception

Returns a record set for all inward linked records.

Parameters:

hint - the hint of the next records.

base - The base object to start our journey

Returns:

The record set.

Throws:

java.lang.Exception - A serious problem occurred.

getResult

@CheckReturnValue
 @Nonnull
public final DBResult getResult(@Nullable
                                                            DBObject base,
                                                            @Nullable
                                                            HintField hint,
                                                            int type)
                                                     throws java.lang.Exception

Returns a record set for all inward linked records.

Parameters:

hint - the hint of the next records.

base - The base object to start our journey

type - the type

Returns:

The record set.

Throws:

java.lang.Exception - A serious problem occurred.

getSteps

@CheckReturnValue
 @Nonnull
public Link[] getSteps()

Returns a list of links that make up this path. INTERNAL USE ONLY.

Returns:

The list of links

getBaseClassConcrete

@CheckReturnValue
 @Nullable
public DBClassConcrete getBaseClassConcrete()

The DBClass that is the base of this path.

Returns:

The base DBClass

parse

protected void parse(@Nonnull
                     java.lang.String thePath,
                     DBClassConcrete baseClass)
              throws InvalidPathException

Parameters:

thePath -

baseClass - The base class

Throws:

InvalidPathException

createLink

protected Link createLink(java.lang.String thePath,
                          VirtualDB layer,
                          DBClassConcrete baseClass)
                   throws InvalidLink

LookUpPath add behaviour

Parameters:

thePath -

layer - the layer

baseClass - The base class

Returns:

the value

Throws:

InvalidLink